f4 key not working, possible solutions?

I have been trying to get this mpc2kxl up and running.. Installed 32mb ram and in process of installing the card reader. I was pressing buttons and the F4 key seems to be not doing anything. Called my tech he said first thing to do is try to shoot some contact cleaner between the buttton and the metal case, then press the key several times to see if some dust or foreign material becomes dislodged. He also said if the part needs replacing I may or may not be able to do it myself. No detectable difference between the other function keys and this one, so I think the key itself isn't damaged.. Anyone have to deal with this situation? What solved the problem?

try deoxit or solder in a new tact switch.

Where are the tact switches available? Thanks ..edit.. looks like mpcstuff has them.. maybe others as well..

save some cash, check this thread:
viewtopic.php?f=1&t=144769&hilit=tact+switches

i just ordered 50 of them yesterday for 10 bux flat! from the website in that thread ^^^^

Woah.. You know, I may seem lazy to a veteran on the mpc forums, like why didn't I look search this up? The thing is there is so many topics on this forum, and many that repeat. Honestly I thought this was gonna be tough to fix. Now I'm finding out about the many DIY'ers around here who have already blazed the trails.. I have to say thanks! For all who have been patient with this newbie..